Blood in Urine

Hematuria is a clinical term referring to the presence of blood, specifically red blood cells in the urine. Whether this blood is visible only under a microscope or present in quantities sufficient to be seen with the naked eye, hematuria is a sign that something is causing abnormal bleeding in the patient’s genitourinary tract. The source of the bleeding can be located anywhere along this tract: the kidneys, the ureters (the tubes running from the kidneys to the bladder), the prostate gland (in men), the bladder or the urethra (the tube that carries urine from the bladder out of the body).

The bleeding may happen only once or it may be recurrent. It may or may not be accompanied by pain or discomfort during urination, and it can indicate different problems in men than in women. The cause may be as routine as an infection or as serious as cancer. Whatever the circumstances, hematuria should be regarded as a danger signal demanding immediate attention. Only a thorough physical examination and medical evaluation can interpret its meaning, determine its cause, or provide the patient with facts needed to make informed decisions about its treatment.

Types of Hematuria

There are two basic types of hematuria.

• Microscopic hematuria, as its name implies, refers to blood present in the urine in amounts so small that it can be seen only under a microscope. All normal, healthy people excrete up to 85,000 red blood cells (RBCs) a day. A typical urine sample viewed under a microscope at 40-power magnification would disclose one or two RBCs. For this reason, some doctors consider hematuria to be present when more than 2 to 3 RBCs per sample are found. Other more conservative physicians believe the presence of any RBCs on more than one occasion indicates a need for further evaluation.
• Gross (or macroscopic) hematuria is visible to the naked eye. The urine may be pink or red. It may even contain small blood clots.

It is important to remember that hematuria in any amount is potentially serious. The amount of blood present does not necessarily indicate the relative seriousness of the underlying problem.

Associated Symptoms

In many cases, the appearance of blood in the urine whether gross or microscopic may be the patient’s only outward symptom. Such cases are called asymptomatic. Others may be accompanied by a variety of symptoms ranging from a need to urinate frequently, to a consistent sudden sensation of urinary urgency, to pain in the flank or side, or pain during urination (dysuria). Some cases, particularly those associated with kidney and urinary tract infections may be accompanied by a fever.

A small number of asymptomatic people experience microscopic hematuria with no discernible cause. These so-called idiopathic cases are typical of individuals who for some unknown reason normally excrete a higher proportion of RBCs.

Interestingly, some cases that initially present the appearance of gross hematuria turn out to non-blood related. This condition called pseudohematuria usually is the result of ingested substances that impart a red color to the urine. Excessive consumption of beets or berries, food coloring, certain laxatives and pain medications all can result in a pink or reddish cast to the urine. Like idiopathic hematuria, however, a diagnosis of pseudohematuria can only be accurately made after thorough examination and testing. Persons who notice a change in the color of their urine should always consult their urologist or primary care physician immediately and never assume the condition is benign.

Causes 

Hematuria may result from a great variety of causes. Not all are life-threatening, and some are more serious than others. All require professional medical evaluation and attention, however. The most common causes are:

• Viral infections of the urinary tract and certain sexually transmitted diseases (STDs) particularly in women
• Kidney and bladder stones
• Urinary tract blockages
• Reactions to drugs and medications especially those that “thin” the blood such as aspirin
• Various kidney diseases and disorders
• Trauma such as a strong blow to the kidneys
• Benign prostate enlargement in men over age 40
• Tumors and/or cancer in one or more parts of the urinary system

In its less common forms, blood in the urine is sometimes experienced by joggers and long-distance runners (“jogger’s hematuria”). This is a condition brought on by the repeated jarring of parts of the bladder. It also can be caused by a variety of rare diseases and genetic disorders such as sickle cell disease (also called sickle cell anemia- a hereditary condition often associated with persons of African-American descent), lupus (also called lupus erythmatosus- a chronic disease of the skin, connective tissue, spleen, liver and other organs) and Von Hippel-Lindau syndrome (a rare genetic disease that causes multiple tumors of the brain, spine, eyes, adrenal glands, pancreas, inner ear, testicles and kidneys).

Classification

In evaluating hematuria, particularly gross hematuria, many doctors initially try to narrow the range of possible causes through a process of classifying the stage at which the bleeding occurs during urination (voiding). While classification is not definitive, it often provides a useful indicator for further examination and testing.

• Blood that appears with the onset of urination — initial hematuria — often indicates a problem in the urethra or, in men, the prostate.
• Blood which occurs at the end of urination — terminal hematuria — can reflect disease of the bladder or prostate.
• Bleeding that occurs throughout urination — total hematuria — suggests problems in the bladder, ureter or kidneys.
• In women, hematuria that occurs cyclically with menstruation denotes abnormal tissue growth (called endometriosis) of the urinary tract.
• Blood discovered between voidings, such as stains found in one’s underwear, often signifies bleeding in one or both ends of the urethra.

Hematuria-associated symptoms also can suggest the site and/or cause of bleeding:

• Pain in the flank with hematuria usually suggests a problem in the kidney, caused by trauma or a tumor.
• Hematuria with irritative voiding symptoms — urinary urgency, pain or increased frequency — is a common symptom of bladder cancer.
• If decreased urinary force, hesitancy or incomplete voiding of the bladder are present with hematuria, the problem likely is in the lower urinary tract, although an enlarged prostate constricting the urethra also may be involved. The enlargement may be caused by a tumor, but it also can result from benign prostatic hyperplasia (BPH), a common condition in men over age 40.
• Abdominal pain with bleeding can be caused by inflammation of the kidney or ureter resulting from trauma, infection or a tumor.
• Fever typically indicates the presence of infection, typically of the kidney or ureter.

Diagnosis

After an initial evaluation, a thorough workup of the patient usually follows. For the workup, the physician typically makes detailed inquiries about the patient’s personal and family medical history. Personal questions will focus on a patient’s urinary habits, recent illnesses, injuries and infections, history of kidney stones, recent and past drug use, drinking and smoking, and possible exposure to toxic substances dating back 25 years or more. Inquiries into one’s family history can be made to look for possible inherited predispositions to renal stone disease, sickle cell disease, von Hippel-Lindau Syndrome and other genetic factors.

This process is followed by a thorough physical examination, with particular emphasis on the urinary tract, abdomen, pelvis, genitals and rectum. The extremities and joints also are examined carefully for abnormalities that typically indicate the presence of different kidney-related disorders.

Analyses & Tests

Regardless of the findings of these inquiries and exams, the physician also will want to perform various analyses of the patient’s urine and blood and possibly one or more diagnostic tests.

In cases of suspected microscopic hematuria, a dipstick test usually will be performed. This is a simple test performed in the doctor’s office in which a sample of the patient’s midstream urine is applied to a special chemically treated strip. Agents impregnated on the strip will change color in the presence of even microscopic amounts of blood. The relative intensity of the color change indicates the amount of blood present.

A positive dipstick test usually is followed by a microscopic examination of the patient’s urine which might indicate the presence of a tumor by detecting the presence of cancer cells (urine cytology). A urine culture may be grown from the sample to check for various infections. Similar examinations of a 24-hour collection of the patient’s urine also may performed, and a blood chemistry workup may be prescribed.

Patients whose gross or microscopic hematuria cannot be positively ascribed to an identifiable cause may undergo a cystoscopic examination. The usual procedure employed is called cystourethroscopy an in-office or hospital test in which a small rigid or flexible fiber-optic instrument in inserted through the urethra under local anesthesia. Through it the physician can visually inspect the urethra, bladder and/or prostate. The exam takes about 10 minutes. Some patients experience minor, short-term discomfort with urination or slight spotting of blood for a day or two after cystoscopy. A warm bath may relieve this irritation, and antibiotics may be prescribed to ward off any possible infection.

Another useful diagnostic test used to determine the cause of hematuria is the IVP or intravenous pyelogram. This is a special X-ray procedure in which a colorless dye containing iodine is injected into a vein in the patient’s arm. The dye collects in the urinary system and provides enhanced contrast for a series of X-rays taken over a 30-minute period. This gives the doctor or technician a better image of the kidneys, ureters and bladder and can disclose stones, tumors, blockages or other problems that may cause the bleeding. At the end of the procedure, the patient may be asked to go to the bathroom and empty his or her bladder completely after which a final X-ray will be taken.

Patients who have had a prior allergic reaction to intravenous dye or shellfish should tell their doctor before undergoing an IVP so that necessary precautions can be taken.

Other Tests

Depending on the results of these procedures and evaluations, particularly if the physician has unresolved questions about the possible cause of a patient’s hematuria, he or she may recommend additional tests of the urinary tract. These may include an ultrasound test— an imaging procedure which uses sound waves projected into the body to create a visual image on a monitor — or a computer-assisted tomography (CT or CAT) scan — a procedure which creates a series of cross-sectional X-ray images.

Differential Diagnosis

Ultimately, the purpose of these examinations, tests and evaluations is to determine the cause and location of a patient’s hematuria. In many cases, no specific cause can be attributed. This is good because such a finding indicates the bleeding probably is not caused by stones, cancer or other life-threatening diseases. Eliminating such diagnoses narrows the field of possibilities to a variety of conditions that may correct themselves or be idiopathic. In such cases the patient often is referred back to his or her primary physician for blood tests to check kidney function, blood pressure monitoring and regular periodic checkups. Men over 50 with no clear differential diagnosis should have a yearly PSA (Prostate Specific Antigen) test to screen for prostate cancer. When a specific diagnosis can be made, treatment may range from a simple antibiotic therapy in the case of infection to surgery depending on the source of the bleeding.

• Depending on their size and severity, cancerous tumors or malignant growths in one or more parts of the urinary tract (kidneys, ureters, prostate, bladder, etc.) may be addressed by a wide range of treatments and surgical procedures.

• Hematuria caused by kidney and bladder stones typically requires corrective procedures aimed at removing or breaking up and passing the stones, as well as measures to prevent their recurrence.

• Treatment of trauma-induced hematuria varies according to the severity of the injury and can range from bed rest and close clinical observation to surgical repair or in extreme cases removal of the damaged tissue or organ.

• Hematuria associated with benign prostate enlargement may be treated with a broad spectrum of options ranging from eliminating substances in the diet and over-the-counter medications that irritate the prostate and cause it to swell to surgical removal of all or part of the gland.

An exhaustive discussion of specific treatments associated with differential diagnoses of hematuria cannot be offered here. Treatment is tailored to cause and there simply are too many potential causes — each drawing upon the detailed results of specific clinical tests, diagnostic evaluations and the physician’s observation of patient symptoms — to cover thoroughly and authoritatively in the context of this section.

Bottom Line: Persons seeking information concerning their own symptoms ideally should see their urologist or primary care physician.

Hematuria may result from a broad spectrum of causes that range from non-life-threatening to profoundly serious. Regardless of when or how hematuria appears, it should never be ignored. The patient should regard it as a warning sign and consult his or her primary physician or urologist at the first possible opportunity.